Princess Origami got the best of me this weekend. I saw this link last week and I finally found a sheet of paper that I could use so I just had to give it a try. This started as a piece of 11 x 17 copy paper that I cut down to 8 x 16 - you need a piece of paper with a 2:1 ratio. And that's as far as my math goes on that! I started Sunday morning and finished later in the day - can't say exactly how long it took as there were many stops and starts and hours between some of them. But it wasn't hard when you followed the video linked above.
Here is my Origami Magic Ball - puffed, squished from one side and the other, and collapsed.